A cave automatic virtual environment (CAVE) projection system is a large virtual reality (VR) system, with high degrees of immersion and interactivity. The CAVE projection system can fuse vision, touch, sound and other senses, and can track head movement along 6 degrees of freedom. The principles of a CAVE immersive virtual reality display system are relatively complex. It is based on computer graphics, and perfectly fuses the high-resolution three-dimensional projection display technology, multi-channel visual synchronization technology, three-dimensional computer graphics technology, audio technology, sensor technology and so on. The CAVE immersive virtual reality display system is therefore able to produce a completely immersive virtual environment surrounded by a three-dimensional projection images and can be used by multiple people. At present, real-time high-resolution multi-window content rendering of a complex scene is mainly applied to the CAVE system. The CAVE projection system is a large VR system with high degree of immersion and interactivity. The CAVE projection system is a highly immersive virtual demonstration environment composed three or more (i.e. including three) hard rear-projection walls. An observer is surrounded by the virtual reality system with a plurality of images, and a plurality of projection surfaces form a virtual space. The common CAVE system projection space is a standard cubic structure, and the four independent projection channels finally form a space continuous projection image.
However, when rendering a scene and generating content-based images to output in an existing CAVE system, projection windows should be fixed beforehand, namely, the position and orientation of the projection screen should be fixed. In addition, the projection windows cannot be placed at arbitrary positions, so that the data interaction with the real visual position of a user cannot be carried out, resulting in a poor visual feeling of the user. Moreover, since the process and feedback of image data are adversely affected, the output efficiency of images is decreased.